In relation to a shape of a temperature detecting part of an electronic thermometer, for example, there has been proposed in Japanese Unexamined Patent Publication No. 133030/1988 an electronic thermometer which is attachable to a body surface and has a discoidal shape. However, a temperature detecting part which has been practically used generally has a rod-like shape, and measurement of body temperatures has been conducted by holding or inserting such a temperature detecting part having a rod-like shape under or in a specific site such as an armpit, a rectum, a mouth or the like.
As temperature measuring modes in such electronic thermometers, there have been employed an estimation mode in which a rate of body temperature increase is detected in a predetermined period of time from just after initiation of temperature detection, and a settled temperature is calculated based on the rate of change to indicate the calculated temperature as a body temperature; and an actual measurement mode in which measurement is performed until detected temperatures substantially settle.
A temperature indication mode in an electronic thermometer is such a mode that indication of the maximum value of temperatures of a body is kept, as in the case of a mercury or alcohol thermometer. Accordingly, it is necessary to once reset temperature indication when a subsequent temperature detection is conducted.
In an electronic thermometer, a temperature detecting part is generally made of a metallic material capable of facilitating thermal conduction or a flexible material such as a silicone or the like and formed into a rod-like shape. However, if such a rod-like shaped temperature detecting part is put under an armpit, there are difficulties as follows. In the case of a thin figured parson, it is difficult to stably hold the rod-like shaped temperature detecting part because a gap is likely to be formed under the person's armpit from the first. Particularly in a case of an old person, it is difficult to precisely detect a body temperature because the person's muscle has become weak and flabby and an enlarged gap is consequently tends to be formed under the person's armpit.
In the case of a suckling or an infant, it is not easy to stably and continuously hold the rod-like shaped temperature detecting part over a temperature detecting period of a several minutes, and it is accordingly difficult to precisely detect a body temperature.
In the case of oral thermometry, to prevent a sublingual temperature from being changed by exhalation, it is necessary that a mouth be closed over a period of a several minutes. It is, however, too stringent to impose such a restrained condition on a suckling or an infant. Accordingly, it is difficult to precisely measure a body temperature.
In the case of rectal thermometry, hygienic management such as sterilization of a thermometer is cumbersome. Accordingly, rectal thermometry is not suitable for body temperature measurement in a general household.
On the other hand, temperature measuring mode in an electronic thermometer includes an estimation mode and an actual measurement mode as described above. In the estimation mode, it is necessary to establish a uniform measuring condition by stabilizing a pressing force exerted on an electronic thermometer held under an armpit. In other words, if a gap under the armpit or the pressing force exerted on the electronic thermometer held under the armpit is changed within a period for the estimation, the condition of heat transfer from a body surface to the electronic thermometer is changed to cause a change in rate of measured temperature increase in the course of the measurement. Accordingly, it is difficult to effect precise calculation for the estimation.
In the case of the actual measurement mode, each of temperature measurement, in which an electronic thermometer is held under an armpit under stable pressing force without forming a gap under the armpit over a period of 5 minutes or longer, and temperature measurement, which requires that an electronic thermometer is sublingually and stably held in a mouth while continuing nasal breathing, has been a hurdle to obtaining precise measurements.
Generally, an electronic thermometer indicates a measured temperature in peak hold mode as its temperature indication. It is, however, necessary to once reset the temperature indication after completion of temperature measurement. Accordingly, such an electronic thermometer is not suitable for monitoring a succession of subject body temperatures in real time.
Further, in a general type electronic thermometer, a measured temperature value is shown on a display of the thermometer. This imposes the trouble of reading and recording a temperature indication every time a measured temperature is indicated on a user (a nurse mainly in a clinic or hospital).
With a view to solving the above-described problems, there has bee disclosed in Japanese Unexamined Patent Publication No. 133030/1988 an electronic thermometer which comprises a flexible substrate, a battery as an electric power source and a circuit element which are mounted on the flexible substrate, and a flexible and heat-insulating covering which covers other parts than a temperature detecting part.
In Japanese Unexamined Patent Publication No. 133030/1988, it has been proposed as a means for saving the trouble of recording indicated temperatures to store temperature data, which is transmitted from an electronic thermometer applied to a surface of a body, in a memory of an external device. In Japanese Unexamined Patent Publication No. 133030/1988, however, a wire communication mode is employed in which the thermometer attached to a body surface and the external device are connected by a cable, leading to poor manageability.
Further, in the electronic thermometer of Japanese Unexamined Patent Publication No. 133033/1988, presence of a battery as an electric power source is always required in order to drive the circuit element, and every time battery power is exhausted, it is consequently required to replace an exhausted battery with another. Moreover, there is a problem that when a battery is replaced, a stress is likely to be exerted on soldered part in the circuit element because of the flexibility of the substrate to cause a failure.
Furthermore, when a battery is replaced, the covering having flexibility and heat insulating properties is peeled. This poses a problem in repeated use.
Still further, as means for outputting in the electronic thermometer of Japanese Unexamined Patent Publication No. 133030/1988, there is employed such a mode that a cable is externally connected to a fixed connector provided on the flexible substrate. However, when the external cable is connected to the fixed connector provided on the flexible substrate attached to a body surface, a strong stress is likely to be exerted on the circuit element mounted on the flexible substrate to cause a failure. Further, it is easily supposable that if the external cable is connected to and disconnected from the connector as often as a temperature is measured, it is easily supposable that possibility of a failure increases. On the other hand, in a case where the cable is left connected, if the cable is pulled, an excessive stress can be exerted depending upon the condition of the pulling on the connector of the electronic thermometer and a connector of the cable to cause a failure of the fitting therebetween. Accordingly, it is pointed out that this constitutes a major factor of a contact failure or the like.
A subject with the electronic thermometer of Japanese Unexamined Patent Publication No. 133030/1988 attached on a body surface thereof has such an inconvenience that the subject's own freedom of movement is restricted when the electronic thermometer is connected to an external appliance by a cable. Further, the external appliance and the electronic thermometer are put in a one-to-one relationship to thereby lead to poor working efficiency of the external appliance. On the other hand, if a plurality of input ports are provided with an external appliance and a plurality of electronic thermometers are connected thereto in parallel, cost of the external appliance per se is increased, and besides this, each of subjects has an inconvenience of being put under a further restrained condition in order to prevent a plurality of cables from being entangled.
The electronic thermometer of Japanese Unexamined Patent Publication No. 133030/1988 interiorly comprises an electric circuit, a temperature detecting part and a temperature measuring means, and further comprises a battery as an electric power source and a fixing hardware for the battery, an output connector, a covering having heat insulating properties and the like to form an integrated structure. The structure as a whole has many parts, and from the viewpoint of being a device which is applied to a body surface in use, it has a problem of incompatibility between thickness and flexibility Further, the largeness in number of the parts leads to cost increase. In view of this, the structure has a hurdle in terms of as a disposable type.
Alternatively, if it is intended to output data from the temperature measuring device to an external device by means of optical communication and to receive the data by a phototransistor, absence of a light-intercepting object between the temperature measuring device as a light-emitting side and the external device as a light-receiving side is required. Accordingly, during temperature measurement with the temperature measuring device applied to a body surface of a subject, the subject is not permitted to cover the temperature measuring device with clothing or the like. It follows that the body surface and the temperature measuring device are exposed to ambient air. In consequence, there is a critical problem that a temperature of the body surface is influenced by a temperature of the ambient air to hinder precise measurement of the body temperature of the subject.
If it is intended to measure a body temperature in real time with the electronic thermometer of Japanese Unexamined Patent Publication No. 133030/1988, it is required to align optical axes of the electronic thermometer as a light-emitting side and a light-receiving side by inserting an optical fiber for light reception into clothing and leading to a vicinity of a connector for light-outputting of the body temperature measuring device with a body surface and the body temperature measuring device covered with the clothing. For this purpose, a member for fixing the optical fiber for light reception to the body temperature measuring device in some manner is required to result in a complicated structure and cost increase. In this regard, even if the body temperature measuring device and the light-receiving side as a data-receiving side are not electrically connected, this fiber-optic communication mode is not substantially different from a wire communication mode so long as the optical fiber is present. In such a fiber-optic communication mode, relationship between the body temperature measuring device and the data-receiving device is one-to-one during measurement, that is to say, the data-receiving device is used by only a single subject. This gives rise to a problem of poor efficiency.
Further, the electronic thermometer of Japanese Unexamined Patent Publication No. 133030/1988 employs, as a means for detecting a temperature of a subject, a means in which a thermistor is brought into direct contact with a body surface. However, if it is intended to perform temperature detection with a thermistor chip as a temperature data detecting means in direct contact with a skin as a body surface, stable contact with the surface of the flexible skin is not always obtainable. Accordingly, it is impossible to effect precise measurement of a temperature of a subject.
The present invention has been made in view of the above-described problems inherent in the conventional techniques. It is, therefore, an object of the present invention to provide a temperature measuring device and a temperature measuring method which are capable of obtaining precise measured temperature values with respect even to old persons, sucklings or infants, which are capable of relieving troubles of monitoring and recording temperatures of subjects, which are simply operable and less susceptible to troubles to permit stable operation, which device comprises a small number of parts and may be formed into a disposable type according to need, which method is carried out by means of such a device, and which enable precise temperature measurement in real time.